1. Field of the Invention
The present invention relates to a control system and methods of operating a refrigeration appliance for controlling the operation of the fan motors for the evaporators and/or condensers of the refrigeration circuit to reduce the total energy consumed by the refrigeration appliance.
2. Description of the Related Art
Refrigeration appliances usually include a control system which determines the temperature of an interior compartment of the refrigeration appliance and turns the compressor of the refrigeration circuit on when cooling of the compartment is required. After the compartment is sufficiently cooled, the control system turns the compressor off. In a typical refrigeration appliance, the compressor is electrically connected to an evaporator fan motor for circulating air over the evaporator and into the interior compartment of the appliance, when the compressor is turned on. In such a system, the compressor and the evaporator fan motor are simultaneously turned on when cooling is required and simultaneously turned off when cooling is no longer required. The compressor may also be electrically connected to a condenser fan which is simultaneously turned on and off with the compressor for circulating air over and removing heat from the condenser of the appliance.
Such conventional refrigeration appliances suffer from certain inefficiencies and an important aspect of this invention lies in recognizing, and providing a solution for overcoming, such inefficiencies. For example, in a conventional cycle, the compressor and evaporator fan motor are turned on simultaneously but there is little or no benefit to circulating air over the evaporator until after the compressor has operated for a sufficient time interval for the evaporator to reach its cooled operating temperature. In addition, the compressor and evaporator fan motor are turned off simultaneously and the cooling capacity of the evaporator, which has been cooled to its operating temperature, is not utilized and is simply allowed to dissipate as warm refrigerant migrates from the condenser into the evaporator.
In a conventional cycle, the compressor and condenser fan motor are also turned on simultaneously but there is little or no benefit to circulating air over the condenser until after the compressor has operated for a sufficient time interval for heat to build up in the condenser. In addition, after the compressor and condenser fan motor are turned off simultaneously, no air is circulated over the condenser to draw heat off of the condenser while it is at its peak temperature.
Accordingly, it would be an improvement in this art if there were provided a control system which would avoid the inefficiencies of operating the evaporator fan before the evaporator reaches its operating temperature and which would utilize the cooling capacity of the evaporator after the compressor is turned off instead of allowing that cooling energy to dissipate. In addition, it would be an improvement in this art if there were provided a control system which would avoid the inefficiencies of operating the condenser fan before the condenser reaches its operating temperature and which would still provide air circulation over the condenser to draw heat off of it even after the compressor has been turned off.